Tiny microphones are moving us toward a world where all gadgets can respond to a voice command

If every tree falling in every forest might soon be heard by an internet-connected microphone, what hope is there for our privacy?

Already when you’re sitting in a room with an iPhone, an Apple Watch and a smart assistant like Amazon Echo or Google Home, you’re surrounded by a dozen microphones. (Newer iPhones have four and the Echo has seven, while the smartwatch has just one, for now.)